TC1796
Peripheral Units (Vol. 2 of 2)
Fast Analog-to-Digital Converter (FADC)
User’s Manual
26-8
V2.0, 2007-07
FADC, V2.0
The conversion result for FADC channel x is given by the following equation:
(26.1)
The absolute value of the result
V
Mx
is limited to
V
FAREF
. The mapping of the conversion
result
V
Mx
to the binary result RCHx.ADRES is as follows (see also
For single-ended measurements, the following values are taken into account:
•
if ENP
x
= 0 then
V
FAINxP
=
V
FAREFM
•
if ENN
x
= 0 then
V
FAINxN
=
V
FAREFM
26.1.2
Conversion Timing
The conversion time of the FADC is determined by the frequency of clock
f
FADC
. The
conversion time defined below includes sampling, converting, and storing of the
conversion result.
(26.2)
Clock
f
FADC
is generated outside the FADC kernel in a product specific clock control unit
(see
V
Mx
= -
V
FAREF
leads to RCHx.ADRES = 00 0000 0000
B
V
Mx
= 0
leads to RCHx.ADRES = 10 0000 0000
B
V
Mx
= +
V
FAREF
leads to RCHx.ADRES = 11 1111 1111
B
Conversion Result
V
Mx
GAIN
x
V
FAINxP
V
FAREFM
–
(
)
V
FAREFM
V
FAINxN
–
(
)
+
(
)
=
with
V
FAREFM
V
FA
GND
V
FAREF
V
FAGND
–
(
)
2
⁄
+
=
Conversion Time
FADC
21
1
f
FADC
-------------
×
=
